Engine-starter.



E. J. TOMLINSON ENGINE STARTER.

APPLICATION FILED MAR. 9. 1917.

Patented Apr. 16, 1918 E. J. TOMLINSON.

ENGINE STARTER. AP PLlCATlON FILED MAR. 9,1917.

- 1,262,873. Patented Apr. 16,1918.

2 SHEETS-SHEET 2.

m! L/E U 1% ED MR2 q. 7' U ML/N SUN HTTURNEV UNITED STATES PATENT OFFICE.

EDWARE J. TOMLINSON, OF NEWARK, NEW JERSEY, ASSIGNOR T0 SPLITDORF ELECTRICAL COMPANY, OF NEWARK, NEW JERSEY.

ENGINE-STARTER.

Specification of Letters Patent.

Patented Apr. '16, 1918.

Application filed March 9, 1917. Serial No. 153,542.

v To all whom it may concern:

Be it known that I, EDWARD J. TOMLIN- soN, a citizen of the United States, residing at Newark, in the county of Essex and State actuated, into operative driving relation with the engine to be started, and also is further adapted to pass automatically out of such driving relation after the engine is started and runs. of its own accord. In starters of this character it is the usual custom to employ an electric motor of suitable design, and so arranged as to be capable of applying its rotative effort, through the medium of suitable driving devices, to the flywheel of the engine. Among the different driving devices now in use for thepurpose of operatively connecting the motor to the engine is the so-called Bendix drive, which comprises, in general, a screw threaded drive shaft having a pinion threaded thereon for longitudinal movement. drive shaft is mounted upon an extension of the motor shaft or upon some shaft driven thereby and has interposed, therebetween a yielding meansin order tor elieve the shock as said pinion passes into its engagement.

The object of the present invention is to improve the manner in which a drive of-this class is associated with the operating motor, by bringing the same into a closer and more systematic relation with each other. In this way I find that various parts of the device may be made of a much simpler design, that certain other elements may be dispensed with, and that on a whole the starter. is

- rendered a more compact and efficient organization of members.

Another object which I derive by thus simplifying and improving the arrangement of engine starters is the marked reduction 1n the cost 'of manufacture, and also a considerable decrease in-the space necessary for installat on.

The adaptation-'- of my invention will be better understood from a consideration of theifollowing description which 15 given in The connection with the accompanying drawmgs.

In said drawings Figure 1 is a longitudinal plan view showing a starting motor, the driving members, and the mode in which they are associated with the motor. In this view the motor frame, pole pieces, and the drive housing are seen to be in section.

Figs. 2 and 3 are reduced scale views of a similar character to Fig. 1, but illustrating other forms in which my invention may be embodied, and Fig. 4 is a plan view (not drawn to scale) of one of the laminations of which the motor armature is built up.

Referring particularly to said drawings,

the character 1 indicates the field frame and housing of an electric motor to which is fixed any suitable number of pole pieces 2. F astened to the field frame 1 is an end plate or bearing head 3 which furnishes one of the motor bearings 4. Coupled directly to said frame 1, as by means of shouldered flange 5, is a member 6 which serves as a housing for the driving elements of the starter, and preferably assumes some suitable shape such as that shown in the figures. This drive housing member may be securely fixed to the motor casing by means of bolts. The extreme outer end of housing 6 is preferably tapered somewhat to give the bearing 7, which, as will presently be seen, serves with the bearing 4 to furnish the support for the rotatable members of the device. An integral flange 8 situated at any suitable point on the drive housing provides a means' .for attaching the starter to the frame of an engine. 9 is a lug formed integral with the motor frame and likewise provides a means of attachment.

4 Considering Fig. l, 10 is a plain shaft of uniform diameter, extending throughout the motor and. drive housings and journaled at either end in the'bearings & and 7. Sparingly fitted upon that portion of shaft 10, which lies within the motor housing, so as to be slightly rotatable thereabout is a hollow shaft 11. Securely fastened upon the end of shaft 11 is an annular ring or collar 12 which is provided with a plurality of rods 13 extending laterally therefrom in substantial parallelism with the axis of said shaft.' In the present embodiment I use three such rods, one of which is shown in dotted lines, although if desirable more may be used. The purpose of these rods is to provide a means of-assembling and securing the armature core 14. As above noted the pins 13 are first secured to the lamination assembly collar 12, which is fitted upon hollow shaft 11, and then the laminations 15 are assembled thereon, and the rods rlveted so as to hold the construction firmly 1n place. In the manufacture of the armature laminations 15 the same are stamped out of thin stock, the conductor slots 16 and shaft opening 17 being preferably punched at the same operation. During this operation such deviations and imperfectlons of the punching tools as may reasonably be expected to occur in shop practice frequently result 1n an angular variation of the spacing of the slots 16. As a consequence when the several laminations are subsequently assembled the relative arrangement may be such that the conductor slot is considerably distorted throughout the axial length of the armature. Such an event means that, in order to avoid difiiculty in winding, the slots must be filed or otherwise corrected of their irregularity, which is objectionable in that the insulatlon coating on the laminations is destroyed thereby magnifying the undesirable effect of eddy currents. To avoid this I have adopted the method of assembling the laminations on the rods. 13, referred to, and have spaced the punched holes 18, whereby each lamination is assembled upon said rods, at unequal angles such as 100, 120, and 140 degrees. In this way it is imposslble to assemble said laminations upon rods 13 so that slots 16 will. occur in anything other than the same relativity in which they are punched. Hence any deviation of the punching operation is thereby taken care of and evenly arranged slots are always assured. A suitable plate 19 provides a clamping surface against which the rods 13 are headed as shown.

Mounted upon shaft 10 is a screw threaded sleeve 20 having collars 21 and 22 at either end thereof. A bolt 23 passing through collar 21 and shaft 10 fixes the screw threaded sleeve for rotation with said shaft. A weighted pinion 24 threaded upon sleeve 20 is adapted, upon rotation of the shaft 10, to move out against collar 22 low shaft 11 to assist inholding said collarthereon. Upon the other end of the hollow shaft 11 the usual commutator 27 is mounted for rotation therewith.

.1 and gear housing 6 which has beenordi- In operation, when power is applied, to the motor armature from some suitable source (not shown) said armature begins to rotate and through the spring 25 rotates the, screw sleeve 20 and plain shaft 10. Imz-iediately the pinion 2 1, which in the drawings is shown in its inoperative position, begins to move into mesh with some suitable toothed wheel. When said pinion reaches the collar 22, and hence further relative rotation with sleeve 20 ceases, the driving load, rather than being suddenly jumped, onto the armature 14, is gradually applied thereto through the yielding medium of spring 25, said hollow shaft 11 rotating slightly with respect to shaft 10 as tension is applied to the spring. The unmeshing process need not be mentioned as the operation of this class of starter drives is well" known.

Fig. 2 shows a construction somewhat similar to Fig. 1 except that the armature 14 is assembled on the armature assembly collar by means ofrods 13 and then placed upon shaft 10 as a unit, without the aid of a hollow shaft for said armature. A through bolt 28 secures the collar and armature rigidly upon said shaft. In this case the collar 21 and the screw sleeve 20 are mounted loosely so as to be slightly rotatable with respect to shaft 10 in order to permit spring 25 to take up the shock of, engagement as explained.

Fig. 3 illustrates an embodiment wherein the sleeve 20 of Fig. l is eliminated and the threads cut directly upon shaft 10 as seen at 29. A construction of this character makes it possible to reduce considerably the size of thescrew threaded shaft without dangerously approaching the safe limit, which is not possible where a hollow threaded sleeve is employed. This permits of a pinion having fewer teeth of the same pitch and hence a greater speed reduction. Another feature of this embodiment is that the clamping plate 19 is made like a cup, having a sleeve portion 30. Said sleeve 30 serves as a means upon which the commutator is mounted. lVhen the parts are thus associated the armature core and commutator may be verv quickly placed upon the shaft 10 and the spring 25 fastened in place.

Among the features of my invention is, as has been well explained, the intimate manner of associating the driving members with the motor armature. Another characterization, which greatly reduces the cost and also the length, .is the fact that I am enabled by my construction to do away with the intermediate head and bearing between the body narily used heretofore, and to connect the driving elements directly to the collar 12 which constitutes a portion of the armature core assembly. Again by using a plain shaft and eliminating the intermediate bearing head the manufacturing cost is reduced since it is not necessary to machine the shaft with many shoulders thereon as is the present custom, for instance, such as a backing shoulder for the core lamination, one for the commutator 'to seat against when forced on the shaft, and also one adjacent the shaft bearings.

It is to be understood that such changes and alterations to which my invention is susceptible may be made without departing from the spirit thereof. I do not therefore desire to be limited to the exact details of construction shown and described, it being believed that all such changes fall within the scope of the appended claims.

Having thus described my invention what I claim is:

1. In a starter for engines, the combination of, a shaft and bearings therefor, an electric motor having its armature on a hollow shaft, said hollow shaft being arranged upon said first shaft so as to be slightly rotatable with respect thereto, said first shaft having screw threaded means on one portion thereof and a pinion mounted thereon to move automatically into and out of engagement with a member of the engine to be started, and a spring resiliently and drivingly connecting said screw threaded means directly to the armature of said motor.

2. In a starter for engines, the combination of, a shaft and bearings therefor, an electric motor having its armature mounted on a hollow shaft, a collar fixed to said hollow shaft and means for fastening the core of said armature to said collar, said armature and its hollow shaft being loosely mounted upon said first shaft and adapted for partial rotation relative thereto, automatic screw threaded engaging means on said first shaft, and resilient driving means connecting said last mentioned means to the collar on said hollow armature shaft.

3. In a starter for engines, the combination of, a main shaft with bearings at either endthereof, a hollow shaft loosely arranged upon and partially rotatable with respect to said main shaft, a collar secured to said hollow shaft having clamping rods fixed thereto; an electric motor having its armature coi'e assembled on said hollow shaft and secured in place by means of said rods, screwthreaded driving means on said main shaft,-

and resilient means connecting the same directly to said armature.

4:. 111a starter for engines, the combination of, a main bearing shaft, a motor and its armature, an armature assembly collar arranged about said shaft, fastening rods serving to secure the core of said armature to said collar, screw threaded driving means located on theend of said shaft and adapted to automatically engage and drive some member associated with the engine. to be fastened to said driving means and the other end to said armature assembly collar, whereby said armature is yieldingly connected to the driving means.

5. In a starter for engines, the combination of, a main bearing and drivin shaft having screw threads cut on one end t ereof, a motor with its armature loosely mounted upon the other end of said shaft, a collar and means for securing the core of said armature thereto, a pinion mounted upon said screw threads to drivingly engage the engine to be started, and a coiled spring yieldingly and drivingly connecting said shaft directly to the core of said armature.

6. In a starter for engines, the combination with a motor including an armature, a housing, an armature shaft journaled at its ends in the housing, of a screw threaded driving means surrounding the armature shaft and driven by the armature of said motor and adapted to automatically engage I tened directly to the armature core structure.

7. In a starter for engines, the combination of, a main shaft with bearings at either end thereof, a hollow shaft loosely arranged upon and partially rotatable with respect to said main shaft, a collar secured to said hollow shaft, an electric motor having its armature core assembled on said hollow shaft and securely fixed to said collar, screw threaded driving means on said main shaft, and resilient means connecting the same directly to said armature.

8.In a starter for engines, the combination of, an electric motor having an armature, an armature assembly collar, a clamping plate with an integral sleeve thereon, means coacting between said collar and plate to secure the core of said armature in its assembled position, a screw shaft upon which said armature is mounted for partial rota tion relative thereto, means on'said shaft to automatically engage the engine to be started, and resilient means interconnecting said shaft and armature, the sleeve of said clamping plate serving as a mounting means for the commutator of the motor.

9. In a starter for engines, the combina tion of a field frame, an armature having a shaft adapted to rotate within said field frame, a bearing attached to said frame for one end of said armature shaft, a screw threaded driving means adapted to automatically engage and drive the engine to be started, an extended housing member attached to said frame for inclosing the screw end of said housing for the other end of said armature shaft, and a resilient member drivingly connected between said armature and said driving means.

- 10. In a starter for engines, the combination of a field frame having a relatively short bearing support on one side and a relatively long bearing support on the other side thereof, an armature having a shaft adapted to turn in said bearing supports, a screw threaded driving means located between the armature and the long outer bearing and adapted to automatically engage and drive the engine to be started, and a resilient member drivingly connected between the armature and said driving means.

11. In a starter for engines, the combination with a motor including an armature, a housing, an armature shaft journaled at its ends in the housing, of a screw threaded driving means surrounding the armature shaft and driven by the armature of said motor, a gear wheel carried on the driving means and adapted to move automatically into and out of engagement with the engine to be started, and a resilient member having one end connected to said driving means and I the other end fastened to the armature core structure.

12. In a starter for engines, the combination with a motor including an armature, a housing, an armature shaft journaled at its ends in the housing, of a screw threaded sleeve ournaled on the armature shaft and adapted to be driven by the armature of said motor, a gear wheel mounted on the screw threaded sleeve and adapted'to automatically engage and, drive the engine to be started, and a spring having one end connected to said sleeve and the other end fastened directly to the armature core structure. 1

In witness whereof I afiix my signature.

EDWARD J. TOMLINSON. 

